Get notified of your Rails app exceptions with Errbit

So, you’ve shipped something

Congratulations!

Now, hopefully, users are coming to use your application, whether a brand new blog system or photo application or whatever great product you created. While you took great length to ensure your application quality (writing specs, testing it manually, etc.), chances are good that one of your user will at some point bump into a technical problem.

Your SMTP server will be badly configured. Your connection to one of the external service will return an error. Validation for the email in sign up form will fail. Browsing a non existing page will trigger a 404 error due to a broken link. An network outage will cause a broken connection to your postgresql database.

The problem is not that it will happen (it will). The problem is that you may never know about it (or far too late), and been left with a buggy product and a dissatisfied user (not all of them will notify you, unfortunately). Even if they stay, you’ll miss the opportunity of doing proactive support by contacting the user directly once fixed.

Now, imagine if you could know exactly which errors happen on your production, with clear information about the server and the request that triggered them.

Enter Errbit.

Errbit

Errbit is an open source implementation of Airbrake, a well known error monitoring tool. Errbit contributors (thanks guys!) has made an API compatible version of Airbrake that you can install yourself. Errbit is (of course) implemented in Ruby (it’s a Rails app).

In a nutshell, once configured properly, Errbit gives you a view of all errors happening in your application, split by environment, and with all the request parameter linked to it – everything you need to reproduce, understand or debug it.

Look at Errbit documentation for the install – I’ll concentrate more on the app side.

To start using Errbit in your application, you need to:

Add the gem to your Gemfile & run a bundle install:

gem 'airbrake'

Configure it in an initializer:

Airbrake.configure do |config|
 config.api_key = ENV['ERRBIT_API_KEY']
 config.host    = ENV['ERRBIT_HOST']
 config.port    = 80
 config.secure  = config.port == 443
 config.environment_name = Rails.env.production? ? `hostname` : Rails.env
end

Note the `hostname` that allows us to get a different environment name for our staging & production (even if both are “production” environment in Rails terms). As usual, the API keys or other secret are in environment variables, as we don’t want those in our source control.

Airbrake will be called for all unrescued exception. You can also decide to call it yourself, even if you do rescue an exception, to add your custom handling:

class ApplicationController < ActionController::Base

  rescue_from APIError: :render_resource_error

  ...

  def render_resource_error(exception)
    Airbrake.notify(exception, airbrake_request_data)
    flash[:error] = exception.message
    redirect_to root_path
  end

end

This code will intercept all “APIError” (whatever what it can be) and route them to a method render_resource_error. There, we notify the end user (using a flash) with a nice message, redirect him to a sure url (the root), and send all the details to Errbit. airbrake_request_data is a “magical” method that Airbrake generates in all your controllers that returns useful info for Errbit to digest (see the source here).

Voila! A nice UI with all your exceptions on the Errbit server:

Now you can see all errors that happen in your application with a single click on your Errbit server bookmark – and get valuable information about them (parameter used in the request, notably). In addition, Errbit group the errors with the same message, so it is very easy to see which are “one time” and which ones come back a lot.

Update: Sidekiq integration

I shared this post on Reddit, and Redditor purephase was kind enough to enrich it with a Sidekiq integration example (Sidekiq is a well known background processor like DelayedJob or Resque). Thanks to him!

in airbrake init:

config.async do |notice|
  AirbrakeDeliveryWorker.perform_async(notice.to_xml)
end

now create an airbrake_delivery_worker.rb:

class AirbrakeDeliveryWorker
  include Airbrake
  include Sidekiq::Worker
  sidekiq_options queue: :airbrake, retry: false

  def perform(notice)
    Airbrake.sender.send_to_airbrake notice
  end
end

Done

Now, of course, you still need to go there to get those exceptions. The good thing is that Errbit can notify you on your email each time it catches a new error. This works well, but we’ve find another solution even better for us – stay tuned.

7 daily use cases of Ruby Array

13 Replies

Ruby and Ruby on Rails come with great reference documentation (Ruby doc, Rails doc, or alternatives such as APIdock, or the recent omniref covering also all gems). But when you need to find how to check if one array has all elements of another, you won’t find the answer in the doc because it’s not use case oriented. The documentation explains what each piece can do, not how you can use it (and clearly not which you should use for a given use case). Of course, that’s the same for tutorial and books. Hopefully, there is StackOverflow. Below, I share 7 common use cases of Array I met very often and should be useful to you.

1. How to check if one Array has all elements of another?

You want to check that all imported emails already exist in a contact list.

imported_emails = [ 'john@doe.com', 'janet@doe.com' ]
existing_emails = [ 'john@doe.com', 'janet@doe.com' , 'fred@mercury.com' ]

puts 'already imported' if (imported_emails - existing_emails).empty?

IRB Output:

already imported
=> nil

Reference: Array Difference

2. How to find what’s elements are common to two Arrays?

You want to find the common tags of two blog posts.

tags_post1 = [ 'ruby', 'rails', 'test' ]
tags_post2 = [ 'test', 'rspec' ]

common_tags = tags_post1 & tags_post2

IRB Output:

 => ["test"]

Reference: Set Intersection

3. How to merge two Arrays without duplicating entries?

You want to get a unique list of twitter accounts id followed by two persons.

followeds1 = [ 1, 2, 3 ]
followeds2 = [ 2, 4, 5 ]

all_followeds =  followeds1 | followeds2

IRB Output:

 => [1, 2, 3, 4, 5]

Reference: Set Union

4. How to sort an Array of Hashes?

You retrieve data from a third party API that returns an Array of Hashes as following:

data = [
 {
    name: 'Christophe',
    location: 'Belgium'
 },
 {
    name: 'John',
    location: 'United States of America'
 },
 {
    name: 'Piet',
    location: 'Belgium'
 },
 {
    name: 'François',
    location: 'France'
 }
]

When displaying those data, you want to sort them by location. You can do it with:

data.sort_by { |hsh| hsh[:location] }

IRB Output:

 => [
     {:name=>"Christophe", :location=>"Belgium"},
     {:name=>"Piet", :location=>"Belgium"},
     {:name=>"François", :location=>"France"},
     {:name=>"John", :location=>"United States of America"}
    ]

Reference: Enumerable#sort_by

5. How to keep objects in an Array that are unique with respect to one attribute?

In an online shop, on the home page, you need to show one product per category.

Product = Struct.new(:id, :category_id)

products = [
 Product.new(1, 1),
 Product.new(2, 2),
 Product.new(3, 3),
 Product.new(4, 1),
 Product.new(5, 3),
 Product.new(6, 5),
]

products = products.uniq &:category_id

IRB Output:

 => [
     #<struct Product id=1, category_id=1>,
     #<struct Product id=2, category_id=2>,
     #<struct Product id=3, category_id=3>,
     #<struct Product id=6, category_id=5>
    ]

Reference: Array#uniq

6. How to filter an Array with a String?

You’ve retrieved a list of books and you want to filter them with a String:

books = [
 'The Ruby Programming Language',
 'Programming Ruby 1.9 & 2.0: The Pragmatic Programmers\' Guide (The Facets of Ruby)',
 'Practical Object-Oriented Design in Ruby: An Agile Primer',
 'Eloquent Ruby',
 'Ruby on Rails Tutorial: Learn Web Development with Rails'
]

books = books.grep(/[Rr]ails/)

IRB Output:

 => ["Ruby on Rails Tutorial: Learn Web Development with Rails"]

Reference: Enumerable#grep

7. How to always get an Array?

In a method you work with products and you eventually return one or several. But when you get only one, it’s not an Array. You can deal very smoothly with both cases with Array() or [*]:

def method
 # …

 [*products]
end

You’ll find more explanations in the Bozhidar Batsov’s post.

Reference: Kernel#Array, splat operator, Ruby Style guide

What’s your daily use cases of Array?

Ruby is full of treasures. It takes some times to know them and find how you can use them. What’s yours? What are your typical daily use cases of Array and beautiful Ruby to resolve them?

TDD your Rails app without convincing your boss

8th Color

Ruby, Code Review, and Development Praxis

Get notified of your Rails app exceptions with Errbit

So, you’ve shipped something

Errbit

Update: Sidekiq integration

Done

7 daily use cases of Ruby Array

1. How to check if one Array has all elements of another?

2. How to find what’s elements are common to two Arrays?

3. How to merge two Arrays without duplicating entries?

4. How to sort an Array of Hashes?

5. How to keep objects in an Array that are unique with respect to one attribute?

6. How to filter an Array with a String?

7. How to always get an Array?

What’s your daily use cases of Array?

TDD your Rails app without convincing your boss